I. Field of the Invention
The present invention relates generally to computer aided design systems and, more particularly, to a method for facilitating the inputting of data representing drawings in computer format to a computer aided design system.
II. Description of the Prior Art
The current trend in high technology manufacturing is to employ computer aided design (CAD) systems as well as computer aided machining (CAM) systems in manufacturing operations. In CAD systems, the engineering drawing for the part and/or tooling to create the part is represented in computer readable form which can be displayed on a video monitor at the CAD system. In many cases, the CAD system generates output data to a CAM system which, in turn, initiates and completes the manufacture of that part or the tooling.
A major disadvantage of the presently known CAD systems, however, is that it is very difficult and time consuming to input the necessary data to the CAD system from a paper engineering drawing of the part in question. Typically, the part is drawn on blank drafting paper and, once drawn, the blank paper is read or scanned by an optical reader.
The optical reader as well as the manual drafting operation, however, is inherently inaccurate. Because of this, after the drawing is read by the optical reader and the output from the reader fed as an input signal to the CAD system, essentially each and every line on the drawing must be individually edited by the CAD operator. Such editing entails manually measuring the distance between an origin on the paper drawing and various points and corners on the drawing. With this information, the CAD operator edits the corresponding point on the CAD system until the entire drawing has been edited and is ready for use in a CAM system.